Pilgrim Geese

I own two pilgrim geese, I do not have room for more as we also have 6 other ducks. The pilgrim goose female has just started laying eggs, but isn't too protective. They live free roam on the lake 12-16 hours a day and go into our shed at night. In the shed, she made a nest and layed two eggs.

My question is, how long does a goose have to sit on an egg to incubate it? She's normally out 14 hours exactly, so she's incubating it for 10 hours.